Electromagnet.



H. G. WEBSTER.

ELEGTROMAGNET.

APPLICATION rILBD SEPT. 23,1907.

1,128,562. Patented Feb. 16,1915

2 SHEETS-SHEET 1.

H. G. WEBSTER.

ELEGTROMAGNET.

APPLIGATION FILED snm'. 28,1907.

1,128,562, 1119111611 Feb. 16, 1915.

Z SHEETS-SHEET 2.

HARRY o. WEBSTER, oF CHICAGO, ILLINOIS, assIGNoR, BY Masiva ASSIGNMENTS, 'ro KELLOGG SWITCHBOARD ec'sUPPLY' COMPANY, A CORPORATION or ILLrNorS.

ELECTBOMAGNET.

Specification of Letters Patent.

Application led September 28, 1907. Serial. No. 395,025.

operation' iespgmsiv'e to varying" cuni-ent values; that*I vone in whose use a'relatively Small current flow will produce one circuit change and a greater current fl'ow will'v alter tli'eciicuit condition produced hy the 'first fr .A. .l A'

The relay of my invention is well adapted forl use in -chnectiony 'with' teleplirine work. It may forfinstaiice be employed for supervisory service in connection with an opera tors connection circuit, in which case the relay initially operatedover a local circuit to display a supervisory signal will be tur ther operated to endv -the isplay 'wlienthe subscriber removes 'his receiver, 'a circuit of lower resistance being thereby established. For such service the relay nius't not' only be responsive to current changes in an ascending ratio, but when the subscriber replaces his receiver producing a current fl'ow of the former lesser value, the relay must operate to again display the signal. This is an eX- acting service to put such a relay to and the relay of my invention is well calculated to meet the requirements indicated.

'I am aware that vvarious double-acting relays are'known in the art, for instance, relays depending on mechanical adjustments of their armatures as by spring tension or weights to render them more or less readily operable.

My present invention realizes its object, to produce a simple and reliable structure of the indicated character, primarily by the employment of two armatures which may be independently mounted, one of which eX- poses a relatively greater area than the other to the electromagnetic action of the core of the relay.

Another feature of the invention is found in a peculiar return magnetic circuit employed which will be hereinafter fully eX- plained. v

Referring to the drawings, Figures l, 2

, specti vely side,

and 3 show respectively top, side and end views of a relay embodying my invention. Fig. 4 illustrates diagrammatically a circuit environment suitable for the relay of the preceding figures. Figs. 5, 6 and 7 are retop and end views of another embodiment of my invention, whereof Fig. S i's a'sectional view. Fig. 9 shows a circuit environment suitable for the relay o Figs. 6 to 8.

Referring first to Fi s. l to 4, the relay consists of a Winding 5 ispsed about a core Ylwhich may have, as indicated in Fig. 3, a pole piece of magneticmaterial narrow above and broader below, the u per part being opposite the narrow anguihr armature 2, while the rlower part is opposite the broader angular armature l, although I am not? limited to this Specific arrangement. Said armatures are mounted, being secured by suitable pins and nuts 13, 14, upon knife edges of the pieces 8`-9, respectively, of magnestic material which extend rearwardly to positions adjacent to, but not contacting with, the distant' end ofthe core, the T shaped iblock of non-magnetic material heilig screwed to pieces 8-9 to support them out of actual c'ontact with thecore. A suitable screw andnut (l1-12) is pro? vided for each armature, the' screws being preferably of brass and arranged for adjust'- able extension through the armatures 1,2 to limit the degree of proniinity to which they may he attracted to'polepiece 6. They are preferably adjusted so that neitheriarmas ture when attracted actually touches pieces 6, as in such 'case there wouldbe a distinct tendency for the rst attracteilarmaturetto magnetically shirtwcircuit' theione'tob af'- tracted last and prevent its actuation. `1It i`s owing to the above consideration that I regard it incertain respects preferable that the customary heel irons 8, 9 Should not contact with the distant end of the cone', there being preferably two gaps of low pen meahility in the magnetic circuit of each armature. l prefer, however, to employ the magnetic pieces 8, 9 for portions of the magnetic circuits from armature to distant end of core, to entirely omit them would roduce an electromagnet of low eiiiciency. Contact spring 3, with its Contact 3, and 4,

Patented Feb. 16, 1915.

with its Contact d, are insulated and mount ed in the usual Way for actuation by their respective armatures 2, l in an obvious and Well known manner.v

1n Fig. Ll, station A Wishing to signal station B, depresses key 17 current flowing from grounded battery l5 through Winding 5 about core 7, through magnet 18 to ground. Armature 1 of greater area is at tracted on the energizationlof winding limited by the resistance of magnet 18, and closes circuit through lamp 16, contact d and contact 3*,since armature 2 of less area is not suliiciently inagnctized to be attracted and open contact 3a. Lamp 16 is now light* ed and the armature of magnet 18 attracted, this attraction constituting the signal at station B. The attendant at B throws switch 19 to engage its upper or lower contact, magnet 18 being in either case.shortcir cuited and a circuit of lower resistance for winding 5 produced, whose energizing effeet upon 'core 7 is increased, which then magnetizes armature 2- of small area suiliH ciently to attract it, Whereon lamp 16 is extinguished and station A knows station B has received the signalq Station B restores vkey 19 where-on armature 2 releases because of the reintroduction of resistance 18 in the circuit, and lamp 16 is again lighted because of the closure of contact 3a, the cur rent being now too slight to hold armature 2 attracted. Station A then knowing the apparatus at B to be in normai condition, releases lrey 17 and the circuit is ready for further work.

In Figs. 5 to 8, the armature 1, of greater exposure area is stirrup shaped'and bent, the armature 2 fitting Within the armature 1. In this embodiment of my invention both armatures are mounted upon heel iron 22 Which is in magnetic contact with the distant end of the core 7, armature 1 being held in place by the pins and nuts 14a. When the relay is partially energized, armature .1 only is attracted, closing contact 21., 20 by actuating spring 21 in an obvious manner. When the relay is more full y energized, armature 2 is attracted and opens contact 21, 2O 'by ac` tuating spring 20. Arniatures 1-2 have the adjustable stops 12-l1 as described for Figs. 1 to 3.

F ig. 9 shows a telephone line circuit C and enough of an. operatcrs cord circuit D to illustrate an application oi' my ,invention On the subscriber removing his receiver, the resulting elevation of the hook lever com pletes a conductive bridge of the line limbs and line signal 25 is energized from battery E in the usual manner. The operator in serts plug F in jack G, the respective tip and sleeve contacts registering and the tip Contact of the jack being raised to disconnect line signal 25. Current new flows from battery through Winding fsleeve, plug aisance and jack contact and over a branch to ground through resistance ,24, another branch path. controlled by the subscribers switch-hook, extending over` the line limbs through. the tip plug and jack contact and to ground through resistance 26. While both branches are closed, both armatures 1 and will be attracted and contact .Q1-20 open, the superi-iscry lamp 27 being then unlighted. ii/Viren, however, the subscriber replaces his receiver, the hook switch opens the conductive bridge of the line limbs, current ceases over the branch through resistance and the current then iowing through .Winding 5 is only suflicient to hold armature 1 attracted, the armature 2 being retracted, contact 20%21 closed and lamp 27 lighted, the display of the latter signaling the op crater to Withdraw plug 1i". Were .the operator to insert plug l" before the subscriber removes his receiver, the dow from battery E through coils 5 and 24 would be sui'cient to cause attraction of armature 1 only displaying lamp lt is apparent that the relay of Figs. 1 to 3 and the local lamp lcircuit of Fig. 4 may be used in the structure of Fig. 9.

Various changes of mechanical arrangementand circuit environment, not departing from the substance of my invention, Will be obvious to those skilled, and I do not limit what 1 claim to the specific apparatus of for energizing the same, a pole piece, an

armature adjustably mounted adjacent to said core having a relatively great airgap area with respect thereto, a second armature similarly mounted and having a relatively small aiigap area with respect to said core, said armatures being supported by said pole piece and switch springs controllable by said armatures.

3. An elcctromagnct comprising a core, a winding therefor, a pole piece, and a pair of armatures adjustably mounted adjacent to said core, one of said armatures having a relatively greater air-gap area With respect to said core than the other, said armatures being supported by said pole piece.

4. A relay comprising a. core, an electromagnetic Winding for energizing saidfcore, a pole piece, a pair of armatures pivotally supported "upon a single alined axis by said pole piece and adapted to be attracted by by said armatures.

5. An electroma et comprising a coil, a return pole-piece or said coil, two angular sha ed armatures pivotally supported by sai pole-piece upon a single ahned axis and a contact controlled by each of said armatures.

6. An electromanet comprising a coil, a return pole-piece or said coil, an angular shaped amature supported by said pole 10 piece, a second armature mounted on said HARRY G. WEBSTER.

Witnees G. E. Mmmm, CAnoLYN WEBER. 

